2003-03-23 Havoc Pennington <hp@pobox.com>

	* bus/policy.c, bus/bus.c, bus/connection.c: implement allow/deny
	policies code

	* dbus/dbus-hash.h: add ULONG hash keys

	* dbus/dbus-sysdeps.c (_dbus_get_groups): new
	(_dbus_get_group_id): new function

6 files changed, 381 insertions, 22 deletions

diff --git a/bus/bus.c b/bus/bus.c
index 4b5b23b5..304faa99 100644
--- a/bus/bus.c
+++ b/bus/bus.c
@@ -41,7 +41,7 @@ struct BusContext
   BusActivation *activation;
   BusRegistry *registry;
   DBusList *default_rules;      /**< Default policy rules */
-  DBusList *override_rules;     /**< Override policy rules */
+  DBusList *mandatory_rules;    /**< Mandatory policy rules */
   DBusHashTable *rules_by_uid;  /**< per-UID policy rules */
   DBusHashTable *rules_by_gid;  /**< per-GID policy rules */
 };
@@ -117,13 +117,26 @@ new_connection_callback (DBusServer     *server,
 }
 
 static void
-free_rule_func (void *data)
+free_rule_func (void *data,
+                void *user_data)
 {
   BusPolicyRule *rule = data;
 
   bus_policy_rule_unref (rule);
 }
 
+static void
+free_rule_list_func (void *data)
+{
+  DBusList **list = data;
+
+  _dbus_list_foreach (list, free_rule_func, NULL);
+  
+  _dbus_list_clear (list);
+
+  dbus_free (list);
+}
+
 BusContext*
 bus_context_new (const char  *address,
                  const char **service_dirs,
@@ -179,18 +192,18 @@ bus_context_new (const char  *address,
       goto failed;
     }
   
-  context->rules_by_uid = _dbus_hash_table_new (DBUS_HASH_INT,
+  context->rules_by_uid = _dbus_hash_table_new (DBUS_HASH_ULONG,
                                                 NULL,
-                                                free_rule_func);
+                                                free_rule_list_func);
   if (context->rules_by_uid == NULL)
     {
       BUS_SET_OOM (error);
       goto failed;
     }
 
-  context->rules_by_gid = _dbus_hash_table_new (DBUS_HASH_INT,
+  context->rules_by_gid = _dbus_hash_table_new (DBUS_HASH_ULONG,
                                                 NULL,
-                                                free_rule_func);
+                                                free_rule_list_func);
   if (context->rules_by_gid == NULL)
     {
       BUS_SET_OOM (error);
@@ -328,3 +341,183 @@ bus_context_get_activation (BusContext  *context)
 {
   return context->activation;
 }
+
+static dbus_bool_t
+list_allows_user (dbus_bool_t           def,
+                  DBusList            **list,
+                  unsigned long         uid,
+                  const unsigned long  *group_ids,
+                  int                   n_group_ids)
+{
+  DBusList *link;
+  dbus_bool_t allowed;
+  
+  allowed = def;
+
+  link = _dbus_list_get_first_link (list);
+  while (link != NULL)
+    {
+      BusPolicyRule *rule = link->data;
+      link = _dbus_list_get_next_link (list, link);
+      
+      if (rule->type == BUS_POLICY_RULE_USER)
+        {
+          if (rule->d.user.uid != uid)
+            continue;
+        }
+      else if (rule->type == BUS_POLICY_RULE_GROUP)
+        {
+          int i;
+
+          i = 0;
+          while (i < n_group_ids)
+            {
+              if (rule->d.group.gid == group_ids[i])
+                break;
+              ++i;
+            }
+
+          if (i == n_group_ids)
+            continue;
+        }
+      else
+        continue;
+
+      allowed = rule->allow;
+    }
+  
+  return allowed;
+}
+
+dbus_bool_t
+bus_context_allow_user (BusContext   *context,
+                        unsigned long uid)
+{
+  dbus_bool_t allowed;
+  unsigned long *group_ids;
+  int n_group_ids;
+
+  /* On OOM or error we always reject the user */
+  if (!_dbus_get_groups (uid, &group_ids, &n_group_ids))
+    {
+      _dbus_verbose ("Did not get any groups for UID %lu\n",
+                     uid);
+      return FALSE;
+    }
+  
+  allowed = FALSE;
+
+  allowed = list_allows_user (allowed,
+                              &context->default_rules,
+                              uid,
+                              group_ids, n_group_ids);
+
+  allowed = list_allows_user (allowed,
+                              &context->mandatory_rules,
+                              uid,
+                              group_ids, n_group_ids);
+
+  dbus_free (group_ids);
+
+  return allowed;
+}
+
+static dbus_bool_t
+add_list_to_policy (DBusList       **list,
+                    BusPolicy       *policy)
+{
+  DBusList *link;
+
+  link = _dbus_list_get_first_link (list);
+  while (link != NULL)
+    {
+      BusPolicyRule *rule = link->data;
+      link = _dbus_list_get_next_link (list, link);
+
+      switch (rule->type)
+        {
+        case BUS_POLICY_RULE_USER:
+        case BUS_POLICY_RULE_GROUP:
+          /* These aren't per-connection policies */
+          break;
+
+        case BUS_POLICY_RULE_OWN:
+        case BUS_POLICY_RULE_SEND:
+        case BUS_POLICY_RULE_RECEIVE:
+          /* These are per-connection */
+          if (!bus_policy_append_rule (policy, rule))
+            return FALSE;
+          break;
+        }
+    }
+  
+  return TRUE;
+}
+
+BusPolicy*
+bus_context_create_connection_policy (BusContext      *context,
+                                      DBusConnection  *connection)
+{
+  BusPolicy *policy;
+  unsigned long uid;
+  DBusList **list;
+
+  _dbus_assert (dbus_connection_get_is_authenticated (connection));
+  
+  policy = bus_policy_new ();
+  if (policy == NULL)
+    return NULL;
+
+  if (!add_list_to_policy (&context->default_rules,
+                                      policy))
+    goto failed;
+
+  /* we avoid the overhead of looking up user's groups
+   * if we don't have any group rules anyway
+   */
+  if (_dbus_hash_table_get_n_entries (context->rules_by_gid) > 0)
+    {
+      const unsigned long *groups;
+      int n_groups;
+      int i;
+      
+      if (!bus_connection_get_groups (connection, &groups, &n_groups))
+        goto failed;
+      
+      i = 0;
+      while (i < n_groups)
+        {
+          list = _dbus_hash_table_lookup_ulong (context->rules_by_gid,
+                                                groups[i]);
+          
+          if (list != NULL)
+            {
+              if (!add_list_to_policy (list, policy))
+                goto failed;
+            }
+          
+          ++i;
+        }
+    }
+
+  if (!dbus_connection_get_unix_user (connection, &uid))
+    goto failed;
+
+  list = _dbus_hash_table_lookup_ulong (context->rules_by_uid,
+                                        uid);
+
+  if (!add_list_to_policy (list, policy))
+    goto failed;
+  
+  if (!add_list_to_policy (&context->mandatory_rules,
+                           policy))
+    goto failed;
+
+  bus_policy_optimize (policy);
+  
+  return policy;
+  
+ failed:
+  bus_policy_unref (policy);
+  return NULL;
+}
diff --git a/bus/bus.h b/bus/bus.h
index eed279e6..56ed5156 100644
--- a/bus/bus.h
+++ b/bus/bus.h
@@ -32,19 +32,25 @@
 typedef struct BusActivation  BusActivation;
 typedef struct BusConnections BusConnections;
 typedef struct BusContext     BusContext;
+typedef struct BusPolicy      BusPolicy;
+typedef struct BusPolicyRule  BusPolicyRule;
 typedef struct BusRegistry    BusRegistry;
 typedef struct BusService     BusService;
 typedef struct BusTransaction BusTransaction;
 
-BusContext*     bus_context_new             (const char  *address,
-                                             const char **service_dirs,
-                                             DBusError   *error);
-void            bus_context_shutdown        (BusContext  *context);
-void            bus_context_ref             (BusContext  *context);
-void            bus_context_unref           (BusContext  *context);
-BusRegistry*    bus_context_get_registry    (BusContext  *context);
-BusConnections* bus_context_get_connections (BusContext  *context);
-BusActivation*  bus_context_get_activation  (BusContext  *context);
+BusContext*     bus_context_new                      (const char      *address,
+                                                      const char     **service_dirs,
+                                                      DBusError       *error);
+void            bus_context_shutdown                 (BusContext      *context);
+void            bus_context_ref                      (BusContext      *context);
+void            bus_context_unref                    (BusContext      *context);
+BusRegistry*    bus_context_get_registry             (BusContext      *context);
+BusConnections* bus_context_get_connections          (BusContext      *context);
+BusActivation*  bus_context_get_activation           (BusContext      *context);
+dbus_bool_t     bus_context_allow_user               (BusContext      *context,
+                                                      unsigned long    uid);
+BusPolicy*      bus_context_create_connection_policy (BusContext      *context,
+                                                      DBusConnection  *connection);
 
 
 #endif /* BUS_BUS_H */
diff --git a/bus/connection.c b/bus/connection.c
index b01cbde6..773ed5ef 100644
--- a/bus/connection.c
+++ b/bus/connection.c
@@ -23,6 +23,7 @@
 #include "connection.h"
 #include "dispatch.h"
 #include "loop.h"
+#include "policy.h"
 #include "services.h"
 #include "utils.h"
 #include <dbus/dbus-list.h>
@@ -48,6 +49,9 @@ typedef struct
   DBusList *transaction_messages; /**< Stuff we need to send as part of a transaction */
   DBusMessage *oom_message;
   DBusPreallocatedSend *oom_preallocated;
+  unsigned long *group_ids;
+  int n_group_ids;
+  BusPolicy *policy;
 } BusConnectionData;
 
 #define BUS_CONNECTION_DATA(connection) (dbus_connection_get_data ((connection), connection_data_slot))
@@ -231,6 +235,20 @@ remove_connection_timeout (DBusTimeout    *timeout,
   bus_loop_remove_timeout (timeout, connection_timeout_callback, connection);
 }
 
+static dbus_bool_t
+allow_user_function (DBusConnection *connection,
+                     unsigned long   uid,
+                     void           *data)
+{
+  BusConnectionData *d;
+    
+  d = BUS_CONNECTION_DATA (connection);
+
+  _dbus_assert (d != NULL);
+  
+  return bus_context_allow_user (d->connections->context, uid);
+}
+
 static void
 free_connection_data (void *data)
 {
@@ -246,6 +264,11 @@ free_connection_data (void *data)
 
   if (d->oom_message)
     dbus_message_unref (d->oom_message);
+
+  if (d->policy)
+    bus_policy_unref (d->policy);
+  
+  dbus_free (d->group_ids);
   
   dbus_free (d->name);
   
@@ -333,6 +356,9 @@ bus_connections_setup_connection (BusConnections *connections,
     }
 
   retval = FALSE;
+
+  d->n_group_ids = 0;
+  d->group_ids = NULL;
   
   if (!dbus_connection_set_watch_functions (connection,
                                             (DBusAddWatchFunction) add_connection_watch,
@@ -387,6 +413,103 @@ bus_connections_setup_connection (BusConnections *connections,
   return retval;
 }
 
+dbus_bool_t
+bus_connection_get_groups  (DBusConnection       *connection,
+                            const unsigned long **groups,
+                            int                  *n_groups)
+{
+  BusConnectionData *d;
+    
+  d = BUS_CONNECTION_DATA (connection);
+
+  _dbus_assert (d != NULL);
+
+  *groups = NULL;
+  *n_groups = 0;
+
+  /* we do a lazy lookup on groups a user is in for two reasons:
+   * 1) we can't do it on connection setup since the user
+   * hasn't authenticated and 2) it might be expensive
+   * and we don't need to do it if there are no group-based
+   * rules in the config file
+   */
+  
+  if (d->n_group_ids == 0)
+    {
+      unsigned long uid;
+      
+      if (dbus_connection_get_unix_user (connection, &uid))
+        {
+          if (!_dbus_get_groups (uid, &d->group_ids, &d->n_group_ids))
+            {
+              _dbus_verbose ("Did not get any groups for UID %lu\n",
+                             uid);
+              return FALSE;
+            }
+        }
+    }
+
+  *groups = d->group_ids;
+  *n_groups = d->n_group_ids;
+
+  return TRUE;
+}
+
+dbus_bool_t
+bus_connection_is_in_group (DBusConnection *connection,
+                            unsigned long   gid)
+{
+  int i;
+  const unsigned long *group_ids;
+  int n_group_ids;
+
+  if (!bus_connection_get_groups (connection, &group_ids, &n_group_ids))
+    return FALSE;
+
+  i = 0;
+  while (i < n_group_ids)
+    {
+      if (group_ids[i] == gid)
+        return TRUE;
+      ++i;
+    }
+
+  return FALSE;
+}
+
+BusPolicy*
+bus_connection_get_policy (DBusConnection *connection)
+{
+  BusConnectionData *d;
+    
+  d = BUS_CONNECTION_DATA (connection);
+
+  _dbus_assert (d != NULL);
+
+  if (!dbus_connection_get_is_authenticated (connection))
+    {
+      _dbus_verbose ("Tried to get policy for unauthenticated connection!\n");
+      return NULL;
+    }
+  
+  /* We do lazy creation of the policy because
+   * it can only be done post-authentication.
+   */
+  if (d->policy == NULL)
+    {
+      d->policy =
+        bus_context_create_connection_policy (d->connections->context,
+                                              connection);
+
+      /* we may have a NULL policy on OOM or error getting list of
+       * groups for a user. In the latter case we don't handle it so
+       * well currently, just keep pretending we're out of memory,
+       * which is kind of bizarre.
+       */
+    }
+
+  return d->policy;
+}
 
 /**
  * Calls function on each connection; if the function returns
diff --git a/bus/connection.h b/bus/connection.h
index f78c3ac1..0d64e987 100644
--- a/bus/connection.h
+++ b/bus/connection.h
@@ -66,6 +66,13 @@ const char *bus_connection_get_name (DBusConnection               *connection);
 /* called by dispatch.c when the connection is dropped */
 void        bus_connection_disconnected (DBusConnection *connection);
 
+dbus_bool_t bus_connection_is_in_group (DBusConnection       *connection,
+                                        unsigned long         gid);
+dbus_bool_t bus_connection_get_groups  (DBusConnection       *connection,
+                                        const unsigned long **groups,
+                                        int                  *n_groups);
+BusPolicy*  bus_connection_get_policy  (DBusConnection       *connection);
+
 /* transaction API so we can send or not send a block of messages as a whole */
 BusTransaction* bus_transaction_new              (BusContext      *context);
 BusContext*     bus_transaction_get_context      (BusTransaction  *transaction);
diff --git a/bus/policy.c b/bus/policy.c
index f916383c..015757a0 100644
--- a/bus/policy.c
+++ b/bus/policy.c
@@ -156,7 +156,7 @@ remove_rules_by_type_up_to (BusPolicy         *policy,
     }
 }
 
-static void
+void
 bus_policy_optimize (BusPolicy *policy)
 {
   DBusList *link;
@@ -175,6 +175,9 @@ bus_policy_optimize (BusPolicy *policy)
    * file.
    */
 
+  _dbus_verbose ("Optimizing policy with %d rules\n",
+                 _dbus_list_get_length (&policy->rules));
+  
   link = _dbus_list_get_first (&policy->rules);
   while (link != NULL)
     {
@@ -208,6 +211,21 @@ bus_policy_optimize (BusPolicy *policy)
       
       link = next;
     }
+
+  _dbus_verbose ("After optimization, policy has %d rules\n",
+                 _dbus_list_get_length (&policy->rules));
+}
+
+dbus_bool_t
+bus_policy_append_rule (BusPolicy     *policy,
+                        BusPolicyRule *rule)
+{
+  if (!_dbus_list_append (policy->rules, rule))
+    return FALSE;
+
+  bus_policy_rule_ref (rule);
+
+  return TRUE;
 }
 
 dbus_bool_t
diff --git a/bus/policy.h b/bus/policy.h
index 00d60baa..680ad581 100644
--- a/bus/policy.h
+++ b/bus/policy.h
@@ -28,14 +28,13 @@
 #include <dbus/dbus-string.h>
 #include "bus.h"
 
-typedef struct BusPolicy     BusPolicy;
-typedef struct BusPolicyRule BusPolicyRule;
-
 typedef enum
 {
   BUS_POLICY_RULE_SEND,
   BUS_POLICY_RULE_RECEIVE,
-  BUS_POLICY_RULE_OWN
+  BUS_POLICY_RULE_OWN,
+  BUS_POLICY_RULE_USER,
+  BUS_POLICY_RULE_GROUP
 } BusPolicyRuleType;
 
 struct BusPolicyRule
@@ -68,6 +67,18 @@ struct BusPolicyRule
       char *service_name;
     } own;
 
+    struct
+    {
+      char *user;
+      unsigned long uid;
+    } user;
+
+    struct
+    {
+      char *group;
+      unsigned long gid;
+    } group;
+    
   } d;
 };
 
@@ -90,7 +101,8 @@ dbus_bool_t bus_policy_check_can_receive (BusPolicy        *policy,
 dbus_bool_t bus_policy_check_can_own     (BusPolicy        *policy,
                                           DBusConnection   *connection,
                                           const DBusString *service_name);
-
-
+dbus_bool_t bus_policy_append_rule       (BusPolicy        *policy,
+                                          BusPolicyRule    *rule);
+void        bus_policy_optimize          (BusPolicy        *policy);
 
 #endif /* BUS_POLICY_H */